Ahh yes, research is done best when it's procrastinated I know...

1963 - The Yardbirds form in London, and later that year Eric Clapton replaces lead guitar.
1965 - Clapton, not liking pop aspirations of the band, leaves. Jimmy Page, a succesful session guitarist is asked to replace him. He instead recommends Jeff Beck, who joins.
1966 - Yardbirds bassist quits, Page volunteers. He soon switches roles with the rythym guitar player. This lasted only a few months...
1966 - Jeff Beck quits, leaving Page with solo lead.
1968 - Introduction of Page's bowing technique and a track called "White Summer" included in the last album released, but without much commercial success, and the band breaks up...leaving Page with the rights to the name and tour dates to honor.
1968 - Page recruits John Paul Jones, who he is familiar with in session work, and Robert Plant and John Bonham (in a previous band together) were introduced and formed...The New Yardbirds. Keith Moon (drummer for the Who) said this band would "go over like a led zeppelin"...